For the past week or so, there have been many speculative assumptions with regard to the number of people who attended the Tea Party rally in Washington on 9/12. And just as many as there were participants, there are unsubstantiated figures that are finding their way into every drollery conversation on this subject matter — hence a volition for creation of this very post. First and foremost allow me to clarify that the intention of this entry is not to reprobate nor to relish admiration for the event or its participants. And I will make sure the comments adhere to orderly civil discourse on the subject matter which is the size estimation of crowd and “nothing else.” We can all find other posts — even on this oft-abandoned blog — to berate and censure each other. Nonetheless, this is NOT one of them. Let me reiterate this again, I don’t care if you are a moonbat leftist or a wingnut rightist; that does not concern me nor should you bring your ideological zeal on this particular post, period.

In theory, a methodology employed for crowed estimation is exceedingly simple: review as many pictures and clips of the event, survey the boundaries in areas where the crowd congregated, examine the density of the attendees in certain range, calculate the area of each segment (in sqft) and finally used the aforementioned data to determine the max and min of people in each block and total the tally at the end. This is easier said than done because of the fact such projection is time-variant. At best, you always wish to take a snapshot of the entire crowd at a given time — hopefully at the most populated moment. Unfortunately, such contingency is not realized when there is no aerial photo at a proper juncture when the area is at its highest population density. So the best possible structural examination I could come up with was to attribute crowd density to each block and run the appropriate calculation base on a following formula:

Σ(Fraction of Crowd with Certain Density) × (Total Area of a Block)/(Density Calculated Based on Square Footage per Person)

The “fraction of crowd with certain density” and “Density Calculated Based on Square Footage per Person” are determined by an overall assessment of photos at the most crowded moment while taking into the account the timing status of other sections with various densities. That is, if two segments of a block, “a” and “b“, at time “t” have crowd density of “d1” and “d2,” respectively, but at time “t1” have crowd density of “d3” and “d4” and d1 < d3, d2 > d4, appropriate considerations are credited in selection for the smallest discrepancy among the recorded densities.

For instance if s < d1 – d2 > 0 (a sign that at time slot t, density of certain segment was greater than a density of that same section at later time, t1, but not bigger than a number, s, which represents a small change) but b < d2 – d4 < 0 (where |b| represents a greater absolute difference among the densities at times t and t1), then the disparity between the density of certain area at various eons becomes self evident. For the sake of fairness, I decided to take the largest density of “a” region with the “least time variant” parameter. That is to say, if the change in the highest density — or even magnitude of a region with certain density (fraction) — is the least altered in a time slot “with respect” to other regions’ density-time fluctuation, then that particular density and the area it represents is chosen.

[???] What does all this concocted technical jargon even mean you may ask? Let me put it in simple words (read: don’t get your hopes high), the best possible areal density evaluation for “a” well defined enclosure is intrinsically interdependent of all the other densities belonging to other mutually exclusive parts (I know, I failed to simplify). We cannot take the crowdedness of one area at time x and have it recorded while using a crowd density of other regions at time y when a) x and y have a large differential gap b) the density of blocks independently varies dramatically from time x to time y[1].

This is crucial when the images and clips are reviewed and their per unit volume discrepancies at different time continuance becomes apparent. It’s like placing 10 people in a first room of a 5-bedroom house and present them to a visitor, then take them to the following remaining rooms, one by one, and at the end, pretend that there are 50 people living in the house with 10 occupants in each room! We simply moved the same group of people around, a sort of rearrangement of units. Same dilemma persists in this case; we can’t simply examine a photo taken at certain time frame, record an evaluated density, move on to the next still which was taken 3 hours later at some location across the field and mark its density and have it used in calculations. Therefore, the ultimate goal is to have a “snapshot” of all the blocks at the vertex of their highest concentrated compactness when the density for all parts differentiates the least in a defined time period — a multi-dimensional matrix of equations with the factorial degree of complexity [1].

Which brings us to the dreaded moment of truth: yes! Ultimately, the main domain for our calculation — density — comes down to one’s “feeling,” albeit the best educated one by analyzing, assessing, and reassessing countless of still imagery and videos and deducing the best possible density for all the blocks. I don’t want to be a bearer of bad news here but the only true way to quantify the figures is to have a live satellite beaming down its lens and having it take snap shots of high resolution photos at short intervals, then have a software program perform a complex array of head count and output a comparatively selected maximum number (good luck locating aunt Sally under a 100-year-old oak tree though) [1].

The biggest misconception arises when the reader assumes that since at time y, certain regions had a much higher density than the earlier times, we must assign a higher density accordingly — that’s a faulty presumption. The reason is, as it has been discussed, we are looking for the snapshot of all the blocks at their apical of density “relative” to every other block. So evaluating a density of block “a” at time y might require readjusting all other block’s crowdedness with respect to time frame y as well which could decrease the density for one or more of the regions and result in inaccurate reading [2].

So when did the rally have the largest number of attendees with the highest density of each block relative to all other areas? Well, according to my chronological examination of thousands of stills and videos, I would put the time frame somewhere around 12:30 PM and 1:30 PM. Also note that the speakers began their scheduled program at 1:00 PM [5].

The “total area of a block” is self explanatory however, it should also be mentioned that due to irregular shape of each block, the calculation of areas was lax and somewhat generous. The map used for this task is taken from Google Map, Washington D.C.-Capitol Hill, in 100ft (50m) echelon (you can verify it by comparing the two in case you are skeptical of diffraction grating offered here). The per person square footage used in calculations are as following:

Extremely Dense: 1.5 × 1.75 ~ 2.5 sqft, after some consideration, it was brought to my attention that 2.5 sqft was indeed a prevailing density for certain enclaves. this might be a contentious figure due to the fact that a regular person, when standing still with arms placed on his side, would take up 3+ ft width-wise and almost 2.5 ft from front to back. However, in very densely packed events (e.g. front rows of concerts), this measurement is in parallel with reality [5].

Dense: 2 × 2.5 = 5 sqft, Some may suggest that taking large fraction of a block as too dense would skew and inflate the numbers unfairly therefore I should attribute them solely to small areas where people are literally embracing each other very tightly. That is true but for the sake of everyone’s elation, I have decided to plug in this density to a larger fraction of each region where crowdedness appears to be palpable. So basically it all comes down to how big a “fraction” or “frequency” of dense area is being considered which eventually plays a bigger role in hyping or lowering the numbers.

Another point that shouldn’t be missed, and I am not trying to disparage or disrespect anyone, is that, from the photos, a certain percentage of the attendees were a bit on a larger side of scale. Again, I’m not trying to generalize or label anyone as being morbidly obese but rather pointing that such actuality should be noted for the sake of accuracy of measurement. Nevertheless, I have decided to forgo the scrutiny and lump everyone as being moderately “fit.”

Moderately-Dense: 3 × 2.5 = 7.5 sqft, this is a more realistic scenario in which, even though people are not crawling on top of each other, manage to stand closely shoulder-to-shoulder by each other.

Relaxed: 4 × 3 = 12 sqft

Breather: 5 × 5 = 25 sqft

Arm-Length: 7 × 5 = 35 sqft, a person can extend his arm freely without physically striking people around him.

Dispersed: 8 × 5 = 40 sqft, this density is extremely close to the previous one and merely used to satisfy certain visual discrepancies encountered in the images.

Happy-Camper: 10 × 6 = 60 sqft

Some suggested to use the marching order to estimate the numbers. To do that, first we have to calculate the area covered from 14th St all the way down to Pennsylvania Ave. and Capitol Hill, area in which each demonstrator environs and make a division, and finally divide them up to tally the number of participants. If the width the Pennsylvania Ave is taken as 100ft and length of the street as more than a mile (i.e. 5500 ft), then the area of that stretch is roughly 550,000 sqft. Assuming each protester takes up around 8-12 sqft while “marching,” then one can speculate that around 50,000 to 70,000 attended the rally. This method does not deliberate on the speed in which the protesters are moving (i.e. 3-5 mph!) and how many could possibly squeeze out of each end of the rally (i.e. 14th and 3rd St.) which could add another 20,000 to the total. I find this particular arrangement unreliable and rather estimate the crowd when everybody is stationary.

Below you can find a map attached to this post where it has been subdivided into 13 areas/blocks (click on the image to access the larger resolution 1305 × 1253, 780 KB). For each block, I will first show the area’s calculation for the colored shape, then proceed to project the max and min of crowd using the formula discussed above, and finally a list of pertinent photos and clips that have been utilized to determine the parameters for the calculation. Moreover, the “majority” of the figures have been rounded “up” except when a calculated number is too close to the lower bound (i.e. 4396 becomes 4500 and 1016 becomes 1000) — of course for larger figures, rounding “up” could mean an increase of 500+ or even 4-digit surge. The direction of compass used to reference blocks and areas in the following section is not of Google Map’s but rather the “northern” point of reference was chosen to be the Capitol Hill. So if one is facing the Capitol Hill, the right hand side becomes east and the left hand side becomes west (in reality this corresponds to north and south in Google Map, respectively).

Another important pointer that I must share is that certain individuals (and I’m pretty sure there are a lot of you out there) who sophomorically might look at a picture and suggest that certain parameters (e.g. density) should be reconsidered with higher degree. Such misinterpretation of an image stems from an optical density illusion (a term borrowed from one of the commentors, cluebattingcage; allow me to elaborate). Such false apparition occurs when eyes view the object — crowd in this case — from a lowered angle which might give a false perception to the fact that there are more of that object than really is. If a viewer take on a higher position, this illusion of numbers (or density) diminishes and ultimately, in birds-eye-view (i.e. satellite images or a photo from a chopper) would allow for better density determination. So keep this in mind as you browse the photos or parse the video clips.

Finally, when I pulled all the germane photos, I also recorded the “time of capture” for each image through image properties (i.e. EXIF data). Reviewing the timestamps reveals that these data are unreliable because not all cameras are synced and many have erroneous configurations. Notwithstanding, I included them after each hyperlink and noted the ones with inaccurate date/time. In many references I use the term “Reflecting Pool” in substitution of “Capitol Reflecting Pool” as opposed to “Lincoln Memorial’s Reflecting Pool.” You can view the original one and Rev. 1 here if you wish to compare progressive readjustment.

A map below is a color coded density of the entire rally. Each colored region represents a boundary in which the crowd had the attributed density, for instance, a blue segment shows that the people located in that area had a 7.5 sqft/person density. You can find legend for color-density key-value below [4]:

2.5 sqft = Olive Drab[5]

5 sqft = Red

7.5 sqft = Blue

12 sqft = Green

25 sqft = Yellow

35 sqft = Orchid

40 sqft = Cyan

60 sqft = Violet Red

No Density = White

Unknown Density or inapplicable = Black

Every picture, still, or clip is also color coded with one or more ticks (“»“) which indicates what set of density was extrapolated from the resource. Note that certain images may depict multiple blocks but the tick merely represents the area in which it is being examined under. For instance, if a still shows block x and y where the density in block x is a and the density in block y is b, and the resource is being presented under block y, then density “b” is what we are interested in, not “a” which belongs to area x. A resource can contain multiple densities therefore one or more colors assign to it [4]. You can find Rev. 1 of density map and Rev. 2 of density map here. Also, I have included the PSD (photoshop) version of density map (~10 MB). Right click on the link and select “Save as” or “Save link as” and download it as “.ppt” and rename the extension to “.psd” because WordPress is picking as to what file format one can upload to their servers [5].

Remember, this is NOT about your bruised ego so keep your mind free of bias and try not to smash the monitor if you “feel” a certain number is too high or too low.

This is an area covered from a line close to the eastern wing of the Capitol Hill building, limited by South Capitol Circle in the south (or lower boundary) and in the north (upper boundary) by the pathway that is the extension of line going through Garfield Circle and Maryland Ave. parking lot all the way to the Capitol Hill steps.

»East of the Capitol Hill taken close to the Independence Ave. — note that the crowd is merely extended to the outer passageway of the east lawn. Even though it appears that people are packed together, it doesn’t make it so because the picture was taken from far away which creates such illusion therefore the density cannot be extrapolate via this image (September 12, 2009 at 12.04pm EDT)

»»On the east lawn close to the Garfield Circle facing the dome. If the timestamps is correct, then a moderately heavier density segment reaches a parallel line to the eastern chamber. What is certain is the 12+ sqft density can be applied to the people closer to the camera (September 12, 2009 at 12.01pm EDT)

»»Facing the US Botanic Garden and South Capitol Circle more to the back segment of the eastern lawn — crowd closer to the camera provide a better understanding of density distribution then rows of planted people on a horizontal space (September 12, 2009 at 12.54pm CDT)

»»»»»Off of Capitol steps facing the Garfield Circle — notice the back of the eastern lawn closer to Independence Ave. and 1st St are empty that’s due to the time lapse which gears toward the end of the rally. In other word, not the best photo to judge the density (September 12, 2009 at 3.31am EDT)

»»» A footage from the terrace area focusing on eastern lawn at 3:40 — again, due to the distance, it’s very difficult to estimate the densities at various parts. However, you can see the eastern lawn is almost fully populated (inside the “outer” pathway)

»»»0:36 – Eastern lawn (earlier into the program, the populated area appears more dense) — once again, since the resolution is low and the angle does not provide a better understanding of crowdedness, we cannot derive at a conclusive density

»»1:55 – back of the Eastern lawn where crowd are more dispersed. Hard to determine at what juncture the crowd density jumps up but examining the position of building to the crowd, we can extrapolate the shot was taken at around center of the eastern lawn but closer to the East Capitol Circle

»» A video taken on the eastern lawn at 2:23 – a lot of folding chairs and seated people.» 2:58 – reveals how far and dispersed the crowd had moved away on the eastern lawn.» 3:31/3:47 – closer to the eastern wing of the Capitol building.» And finally, at 3:59 you could see the pathway which marks the eastern boundary of the rally (no one is visible beyond this line as it has been marked on the map). 4:10 – shows an empty lot between the demonstrators and eastern wing of the Capitol Hill building.»» 5:05 – the edge of the eastern lawn closest to the Capitol steps.» 6:10 – front rows, notice the density.

»»» A video taken on the lower Capitol steps looking at the east lawn (0:42) — start of the program, height of the rally although the camera is a bit shaky and certainly does not provide a much needed resolution and closeness for density determination

» Taken off of the edge of the Garfield Circle and 1st St. facing the eastern lawn — I cannot verify the accuracy of the timestamps however this photo is a damning evidence to the extension of the crowd all the way to the “at least” slightly beyond the “outer” passageway of the eastern lawn and possibly to the 1st St. even though the density does not seem to be heavy (September 12, 2009 at 11.18am EDT)

»»Crowd on the edge of the Garfield Circle facing the Maryland Ave. parking lot — although people sitting on the short wall are blocking most of the view of the Circle, you still can observe the crowdedness of the area (September 12, 2009 at 11.26am PDT

» A video (0:20) on the edge of the Garfield Circle. Hard to say how far the crowd goes back but evidently, the crowd on the eastern edge of the Reflecting Pool is very much dense if not as dense as the rows on the front lawn

» You can see on the left hand side of the photo that the back of the Maryland Ave. is literally empty — the associated text embedded in the image points to the fact that the time of capture was around 1:30 PM ET but not confirmed

» An interviewer strolls around Garfield Circle with Maryland Ave. visible in the background at 8:13 parallel to the Botanic Garden entrance. The lot is pretty much empty which signals the end of the rally as the Circle was indeed pretty much populated earlier on (time of capture could not be obtained)

»» Although not entirely related to this block but on the right side, behind the trees, you can see the back of the Maryland Ave. parking lot — the parking lot is equally congested with people although it’s hard to make up the density (September 12, 2009 at 12.55pm CDT)

I probably shouldn’t have dedicated any numbers to this block because the area was merely designated for organizers and affiliates, media crews, and guests/speakers. However, I saw a few lines of workers in some photos so I decided to include them in my final tally (they turned out to be Coal Industry Workers (0:20) brought to the protest as Cap & Trade was one of the main umbrage of the rally). Note that juxtaposing the images taken from this area with the one highlighted on my map, it becomes apparent that the boundaries represent a smaller region than of reality of the area but I’m willing to forgo of such deviation. Note that I’m marking all the related photos and clips as “unknown density” because there is no point assessing crowd in this particular block.

Rev. 2
Only the area was recalculated but the crowd estimate is not needed for this particular block

This is by far the most crowded block and I attributed higher density to a larger portion of this block. At first glance, it might appear that the block must encompass a larger area but if you observe closely (consult the map), you’ll notice that the block has missing parts such as the two partially carved out circles in the lower edges and also the podium/buffer zone on the top. Moreover, juxtaposing the highlighted eastern and western lawns with the front lawn, such doubt should be immediately vanished.

Rev. 3
The front boundary of block (5) was altered to reflect a more accurate geometric size of the area (winged out on the edges where it meets the walkway stonewalls), hence a slight increase in dimension to 125,000 sqft.

Rev. 2 (Block 5 density map, Rev. 2)
After reviewing a number of stills taken from the buffer zone and specially the ones on the higher ground (i.e. Capitol steps), I concluded that the area of the front lawn is slightly smaller on the boundary aligned with the podium, therefore the recalculation was needed. And the reason for a slight increase despite a deduction of trivial area at the front row is that the prior to the latest recalculation, border boundaries on the left and right hadn’t been extended properly.

»»»An angled shot from the front lawn — again not a good picture to extrapolate density at the back of the block but you can see a more spaciously relaxed areas near the East Capitol Circle (September 12, 2009 at 3.32am EDT

»A view from the Grant Memorial statues facing the dome and front lawn crowd. Obviously, I’m not going to use this particular sill to justify any density as the resolution is too low (September 12, 2009 at 3.10pm PDT)

»» A higher vantage point video of the front lawn and Grant Memorial where crowd standing close to the East Capitol Circle — you can see that there is a lot of space among the crowd on the front lawn closer to the foreground

»» A video at 3:22 captures the vicinity — note that at this point, the rally was winding down so don’t assume the front lawn was as crowd-scarce as it was at its zenith

A block encompassing an area between the Reflecting Pool and the front lawn, bounded from Peace Circle and Garfield Circle on the west and the east, respectively. Note, as the rally progressed, an area starting at the Grand Memorial statues up to the East Capitol Circle became desolate, nonetheless, at the height of the rally, it was crowded. A small “white” half circle is an indication of door-wall placed between block 6 and 5; even though several of videos and photos shows the vicinity almost empty, I included it in the calculation because the increase is trivia however it’s marked on the color coded density map.

»» Facing the Capitol, you can see the crowd walking on the East Capitol Circle — an area between the Grant Memorial and the front lawn was used extensively for people to get across different part of the rally so the crowd density would be capricious by nature (September 12, 2009 at 2.26pm EDT)

»Facing the Grant Memorial on the East Capitol Circle right before the bushes — a great estimation of crowd density (September 12, 2009 at 1.55pm EDT)

»A view from the Grant Memorial statues — although the resolution does not permit to reach a conclusive result, it is necessary to note the crowdedness of this area (September 12, 2009 at 3.10pm PDT)

»» Captured at the Grant Memorial facing the Capitol Hill — not many people present on the Memorial steps, an area behind the bushes adjacent to the East Capitol Circle. It appears that at this particular time, the rally was dwindling down.

»» A video from the higher vantage point of the front lawn and Grant Memorial at 0:09 where crowd standing close to the East Capitol Circle. At 0:22 you notice a circular empty zone due to a stone door frame + bushes planted on the border of block 1 and 6

An area bounded by the closest pathway to the western wing of the Capitol Hill in the north, South Capitol Circle in the West, Peace Circle in the south, and a passageway extension of Pennsylvania Ave. all the way to the Capitol stairs on the east.

»» All the way to back of the western lawn close to East Capitol Circle — given the relative position of the crowd to the Capitol Hill building, folks on the foreground are situated near the outer passageway (September 12, 2009 at 12.27pm EDT)

»» Crowd on the west lawn, near the East Capitol Circle — notice the position of the spot where the picture was taken to the western chamber of the Capitol Hill building; a perpendicular line to the building would go through the middle of the building which incidentally, it is also a middle proximity of the western lawn therefore the extension of crowd you view all the way to the left is expected (September 12, 2009 at 2.14pm EDT)

» Crowd on the edge of the East Capitol Circle close to Peace Circle and 1st St. — after some contemplation, it was brought to my attention that the photo was taken while the crowd was being ushered to the various enclaves, in this particular case, to the west lawn so it’s not much of a still that I would like to utilize to assess certain parameters. Remember, we are looking for images that show stationary crowd, not mobile (September 12, 2009 at 2.46pm PDT)

»» Just like walking in the park. A man with the largest cojones strolls around on the west lawn with the largest “Public Option Now” banner he could hardly hold while being escorted by the crowd and eventually a dozen cops — at 0:35, you could somehow determine his position relative to the Capitol Hill west wing which is inside the “outer” passage way. If so, then the density of this segment of block (7) is more dispersed than I had assumed. However, I cannot determine at what point this video was captured

The reason the Peace Circle and East Capitol Circle are half way highlighted on the map is that at the height of rally, it had been barricaded by the police in order to provide emergency exit route, therefore it was only partially populated. The remaining area extends all the way to Constitution Ave. but I found little evidence to its crowdedness at the back. A black strip along side of the block portrays a row of portable potties installed in that location.

»» Crowd around the Peace Circle — notice that the East Capitol Circle and 1st St NW are left open by the police, not sure if the parking lot on Pennsylvania Ave NW is populated. The juncture area behind the barricades on the foreground (not across the street) was at some point populated (September 12, 2009 at 2.12pm EDT)

»» The first few minutes of this video captures the crowd density in this area as the rally was dwindling down. The story goes that somehow this guy begins accusing a couple of African-American kids who were selling “Don’t Thread On Me” accoutrement as ACORN operatives making “profit” (how un-Capitalist of them) among the crowd! Then he pursues to loudly “expose” them while calling the kid a “boy” (most certainly a poor choice of word but I don’t suppose he was born in the post-racial Utopian era either). He is basically acting all thuggish while dragging his Asian wife when apparently no one is taking a heed to the situation until a few cops quietly escort the family as they walked away from the rally. He is literally out of breath once he drives the musketeers away

» Walking around the Peace Circle — much more laxed and not entirely jammed at this juncture

»» Taken around 1:15 PM, at 3:12 of clip, you can see people gathering in Peace Circle behind the barricades — note that there aren’t as many density packed people as I had initially assumed. However, at 4:27, you can see that a more people congregated at the back rows but then again, Pennsylvania Ave. parking lot was used as an entry and exit point to the rally. Nevertheless, the crowd size and density on the lot is noticeable but can’t tell how far back it goes

»»» A closeup photo of Peace Circle with people behind the barricades – notice the portable potties on the edge of the green space between the 1st St. and Constitution Ave.. The front rows are not as densely as one would hope and if you look closely at the areas in the back, you’ll notice that there is much crowd disparity but from the timestamps, I would conjecture that the rally hadn’t been culminated at the Capitol Hill; either that or the timestamps is inaccurate (September 12, 2009 at 11.26am EDT)

»» A guy with a “Public Option Now” banner crosses the street on “northern” East Capitol Circle at 3:19 while he’s being escorted by hundreds of attendees an eventually a dozen cops — at 3:56 he reached the 1st St.. 4:39, block (8) comes into the view and if you can freeze the video at various points, you’ll notice that it is empty beyond the pathway going from the Circle to Constitution Ave. and behind a row of portable potties. The guy is being encountered by 100’s of Tea Party members.

»» A continuation of the event described above where the “Public Option” fella standing on the edge of the block (8) facing the 1st St. — at 0:55 you could almost take a pick at the area. Not much crowd, as a matter of fact empty. Also note that the majority of crowd on the 1st St. was drawn by his parade and were actually situated there

A parking lot that sits on Pennsylvania Ave and is located to the west of the Reflecting Pool. Rows of portable potties were situated on the side of the parking lot along side of vehicles. The majority of projection of this block was surmised from other areas and also the fact that it was used as sort of a gateway for the attendees to go in and out of the rally.

This is an area designated to the edge of the Capitol Reflecting Pool where usually either one person is sitting or/and having two or more people sitting across the attendee. A distance between this line and the perimeter of the pool was used by the crowd to move around therefore it was left out of the equation due to the fact no dynamic flow of crowd was used in any of the calculations — the golden rule, remember? Nonetheless, at the end, I added 15,000 (initially 5,000, then 10,000) to the final tally to make up for this mobile segment of demonstrators. The entire section has been ticked by the “unknown density” color because the density does not need to be applied.

»» A captured video of the Reflecting Pool perimeter at 4:49 — not as crowded as earlier on.» 6:16, the eastern perimeter of the pool, again not much crowded.» 6:30 – lower eastern edge of the Reflecting Pool, facing to Grant Memorial, practically empty. This must have been at the end of the rally

» A shot taken from the eastern corner of the 3rd St. — notice the crowd congregation on this particular pocket but I am assuming the timestamps must be off by a few hours (September 12, 2009 at 11.57am EDT)

»» Crowd on the Reflecting Pool perimeter facing the Constitution Ave. — the timestamps indicates that it was shot at noon when the rally was about to begin and the most crowded time frame. If that’s true, my highlight map accurately color coded for the amount of populated area that is being shown in this still (September 12, 2009 at 11.58am EDT)

A distance between the perimeter of Reflecting Pool and the 3rd St. which is by itself a large area although, according to several photos, was not used extensively by the crowd (only sporadic groups with folding chairs setup shop there). Notice that the low number on this block is due to the fact the majority of people at the height of the rally were situated closer to the Capitol so they can observe the podium — visibility of the podium at this elevation is almost non-existence. Later on in the day, some attendees shifted to this block.

Many people assume that just because later in a day, a group of attendees migrated to the back areas such as the one between the Reflecting Pool and 3rd St., it constitutes a “new” increase in density in such vicinities — this is a faulty assumption. Remember, the count was set when the density of all the blocks had to be at the highest and at that very time frame, areas on the back were much lighter in attaining participants (most people were huddled at the front)

» Taken from the area between the back of the Reflecting Pool and 3rd St. — due to an erratic timestamp, it is hard to say whether this was a start of the rally or after lunch period when returning people situating themselves on the 3rd St. block (September 12, 2009 at 11.38am EDT)

» Walking across the 3rd St. onto the block at 1:22 (right smack through the middle of the enclave)» 2:22 shows a more concentrated crowd that I have seen in photos but perhaps on a congested crossing zone, this was to be expected. Note that as the rally was wrapping up, many people began dispersing to the back areas, hence the reason for this particular crowdedness. Obviously, the majority of these people were situated on different blocks when the speakers delivered their notes.» 3:32/3:55 show a more dispersed crowd as we have seen in various photos.» 4:21 – a more inclined toward the western side of the 3rd St. area

»» A video taken from the 3rd St. all the way walking to the back of the Reflecting Pool area — it was recorded after the clip shared above and as you can see, the crowd density has increased dramatically. These are the attendees who had gone to luncheon and rather going back on the front lawns, they decided to congregate in a more space-friendly areas, i.e. 3rd St.. This is a clear case of rearrangement

» A short-lived moment taken from 3rd St. at 3:11 facing the National Mall — the density on the perimeter is moderately high but a few rows on the 3rd St. field also “appears” to contain a bit more densely packed crowd. However, if you watch the remaining of the clip, you’ll notice that half of the east and west lawns are half empty which signals the end of the rally therefore I will not consider the density captured on this video in the final estimation

»» A view of the middle of the 3rd St. block — this probably was near the end of the rally where people congregated at the back areas as they came back from lunch (September 12, 2009 at 11.57am EDT)

Rev. 3
Max total crowd ~ 127,500 but after correction, 121,000
Min total crowd ~ 122,000 but after correction, 115,700

Rev. 2
Max total crowd ~ 108,000
Min total crowd ~ 101,000

Rev. 1
Max total crowd ~ 126,000 but after correction, 121,000
Min total crowd ~ 110,000 but after correction, 105,000

Original
Max total crowd ~ 155,000 but after correction, 152,000
Min total crowd ~ 130,000 but after correction, 127,000

However, assuming roughly 10%-15% or 15,000/10,000 max/min (revised from 5,000 for the “Original” estimation, 10,000 for “Rev. 1” estimate, 15,000 in “Rev. 2” for both min/max) of people were streamlining in and out of the rally at a given time (either for food, other necessities, or just scattered around in the areas that were not deemed populated in the highlighted map), the final tally would rise up to:

Rev. 3Max total crowd ~ 142,500 but after correction, 136,000Min total crowd ~ 132,000 but after correction, 126,000

Rev. 2Max total crowd ~ 123,000Min total crowd ~ 116,000

Rev. 1Max total crowd ~ 136,000 but after correction, 133,000Min total crowd ~ 120,000 but after correction, 117,000

OriginalMax total crowd ~ 160,000 but after correction, 157,000Min total crowd ~ 135,000 but after correction, 132,000

There you have it. Prior to all this, my initial anecdotal estimate was somewhere between 90,000 and 110,000, and concurrently, the original evaluated figures came 50% on top. However, after the first revision, the numbers did indeed take a 15% ebb and continued its descend in Rev. 2 until higher density variables were added to the equation [in Rev. 3]. Of course this is assuming my calculation and certain inferences and conjecture of various parameters are accurate.

Recently, it has brought to my attention that certain pro-Tea Party crowd are adamantly promulgating an erroneous figures that either dubiously attained or flagrantly concocted. Let me be blatantly clear about this: the veracity of such claim not only defies rationality of making a silk purse out of a sow’s ears but only confers to its impossibility. Geographically speaking, the entire area encompassing a line drawn parallel to the facade of the Capitol Hill, connecting Constitution Ave. to Independence Ave., enshrouding the area all the way to the 3rd St., would register somewhere around (13 × 14 × 100² ~) 1,820,000 sqft. Even if you manage to cram every single person on top of each other (3.5 sqft/person, an extreme condition only seen on first few crushing rows of a sardined concert), the total crowd would boil down to 520,000. This simple calculation immediately shatters a false presumption that there were millions of attendees or even 800,000 as it has been reported by the official organizers — not only such assertion is patently false and egregious in its nature, but rather entirely unrealistic and improbable.

Moreover, a particularly absurd calculation that I just discussed in the previous paragraph does not exclude areas such as the Reflecting Pool (180,000 sqft), 1st St.-Independence Ave. (130,000 sqft), the US Botanic Garden enclave between 1st St. and 3rd St. (260,000 sqft), tail end of Pennsylvania Ave. and Maryland Ave. parking lots (40,000-50,000 sqft), East Capitol Circle and Constitution Ave, including the 1st Ave and vicinity (90,000 sqft), and other limited pathways such as the ones passing through the Peace and Garfield Circles all the way to the Capitol steps (10,000 sqft) which ultimately brings the total “occupied” (not to be confused with “occupiable”) area to 1,100,000 sqft (1,820,000 – 720,000) — a comparable figure to the total space I come up with. Second, another faulty assumption in our 520,000 figure is that all the remaining populated areas have the same density which is a misleading premise to begin with; all to the contrary, the evidence (photos and videos) attests to that fact. Even if you forgo this rationality and assume the density of 3.5 sqft for the “entire” populated blocks (1,100,000 sqft), that would leave us with around 315,000 attendees which is no where around 7-figure being so shamelessly touted in the echo chambers of gullibility.

It has become apparent that such mis-perception stems from either lack of intellectual rectitude, political zeal (read: cultist mentality), or a clarion of acumen to do a rudimentary research before jumping on a bandwagon fallacy. Disproving an absurdity of this magnitude should not require a considerable effort if one wishes to apply himself accordingly. Examining in contrast of the recent events (i.e. “We Are One” Inauguration Concert with ~500,000 attendees in yellow or Obama’s Presidential Inauguration ~1,000,000 +/- in blue on the highlighted map below), the area occupied by 9/12 Tea Party rally (colored in red with overlapping areas of Obama’s inauguration in purple) in comparison with presidential inauguration should not by any cogent measurement allow anyone to come up with a “2 million” conclusion. I am not going to indulge certain people’s reasoning process by delving into psychological inclination of those who claim otherwise because I would like to keep the focus on examination of facts and facts only, so we leave it there.

Below you can find the colored map for the discussed paragraph (click for the [1st revision] larger resolution 2074 × 545, 760 KB below — I’m totally aware that the map is not entirely accurate and created just to provide an overall contrast between the different events. After the 2nd revision, I readjusted the image to reflect a more accurate coverage of the area. You can find the original highlighted map and 1st revision here).

Now, take a look at a side-by-side contrast between the National Mall field from both events; the one taken on the presidential inauguration day (the one on the top, somewhere after 12th St., Smithsonian tower is visible on the right hand side) which clearly illustrates the sheer number of attendees with the Tea Party’s (somewhere after 7th St. if you wish to verify note that the timestamps was corrected by an hour to 3:03pm EDT) undisputedly portrays an uninhibited field (for another perspective, you can view a picture taken closer to the Capitol Hill around south of the IMAX Theater on the National Mall and even closer and closer). This should leave no doubt that there was in no way the 9/12 event had an equivalent amount of crowd participating in the protest when the presidential inauguration had merely an estimation of around 1 million. Contrarians are delusional if they think otherwise; again, this is not about one’s political affiliation but rather an honest examination of fact vs. fiction [3].

NOTE: I am certainly cognizant of a fact that the maps and the numbers are not entirely flawless and do contain errors, along perhaps some of the calculations or conjectures of assumed parameters. Yes, there are probably tons of grammatical and spelling errors peppered all over the post but I hope you’ll find it in your kind hearts to extend me your clemency. If you also know of a photo set or a video clip that offers a better view from an area that I have missed, please do share it with us. At the end, I would like to invite everyone to do note such omissions and oversights in a civil manner backed with reference and verifiable fact. If such disparity or shortcoming was found, I will surely include them in the “update” sections throughout the post. If somebody can provide me the following research paper titled, “Estimation of Crowd Density Based on Wavelet and Support Vector Machine“, it would be greatly appreciated.

Update (1)

Block 1: An area closer to the Capitol building was slightly trimmed to reflect the exact boundaries for this region. Area, max, and min were recalculated — all decreasedBlock 2: After reviewing several more photos and clips, max and min were recalculated — both decreased by ~40%Block 3: The area was readjusted and max/min reevaluated — all decreasedBlock 6: The area was redrawn to adequately touches certain corners; area, max, and min were recalculated — all slightly increasedBlock 7: The west lawn was redrawn on the map, area, max, and min were reevaluated — all decreasedBlock 8: The crowd density for this block came under question after reviewing multiple clips — all decreasedBlock 9: The area was increased by 2/5 as it was being used as a gateway to the rally for the duration of the protest; the area, max, and min were recalculated — all increasedBlock 11: It was brought to my attention that the back of the Reflecting Pool was more crowded that it had been assessed; max and min were reevaluated — both increasedBlock 12: Same fate as block 11 except that max and min were slightly bumped — both slightly increased

Update (2)

A color coded density map along with resource assignment to one or more density were introduced for better understanding of how each block’s crowd estimate was calculated. Each area was designated appropriate boundaries for various densities extrapolated from multiple resources (i.e. images and videos). All the resources were re-examined and duplicates, omissions, and wrongly attributed items were deleted or reassigned to an appropriate block. The changes as follow:

Block 1: Color coded density map and resources were added. Max and min were recalculated — both decreasedBlock 2: Color coded density map and resources were added. Max, min, and the area were readjusted and recalculated — all increasedBlock 3: Color coded density map and resources were added. Max and min were recalculated — both decreasedBlock 4: Boundaries were adjusted and the only the area was recalculated — it increasedBlock 5: Boundaries were readjusted, color coded density map and resources were assigned. Max, min, and area were recalculated — area was expanded but Max/Min decreasedBlock 6: Color coded density map and resources were added. Max and min were recalculated — both decreasedBlock 7: Color coded density map and resources were added. Max and min were recalculated — both increasedBlock 8: Boundaries were redrawn, color coded density map and resources were added. Max, min, and area were recalculated — area was expanded, Max slightly decreased but Min increasedBlock 9: Color coded density map and resources were added. Max and min were recalculated — Max decreased but Min increasedBlock 11: Color coded density map and resources were added. Max, min and area were recalculated — area was expanded, Max and Min both decreasedBlock 12: Color coded density map and resources were added. Max, min and area were recalculated — all decreasedBlock 13: Color coded density map and resources were added. Max and min were recalculated — Max decreased but Min increased

Update (3)

A new density parameter was added to the list, 2.5 sqft/person which is justifiable when one considers the crowdedness of certain enclaves. I even go as far as calling an exclusion of such density a major mistake in my initial work which is a wrong I’d be gladly make right. In the process, all the necessary images and videos were “ticked” with the designated Olive Darb color and the any density map, including the overall plot, that required change in density waves was adjusted accordingly (you still can view the old block-specific density maps in Rev. 2 sections of each block). A Photoshop version of density map (~10 MB) was offered but remember, once it’s downloaded, the extension (file format) must be changed to “.psd” as I was only able to upload in “.ppt” format.